The Sundance Film Festival, forced online this year by the pandemic, quietly opened to a virtual "standing ovation" for deaf family drama "CODA" Thursday.

Taking its title from an acronym for child of deaf adult, "CODA" follows high-school teen Ruby (Emilia Jones) as she juggles her musical ambitions with her family's dependence on her to communicate with the "hearing" world.

The first in-competition film to stream for remote attendees of the prestigious indie festival, it drew immediate rave reviews, with Variety calling it "tender, lively, funny, and beautifully stirring," and Deadline praising a "breakout performance" from Jones ("Locke & Key.")

"I would say it's the equivalent of a standing ovation," Sundance programming director Kim Yutani told the cast as she hosted an online Q&A immediately after its streaming premiere ended.

The unusual debut is a world away from the flashy, red-carpet screenings and after-parties Sundance typically holds each January high in the Utah mountains, where Hollywood migrates to watch and cut deals for the coming year's hottest indie titles.

Sundance organizers have this year invited industry types to "trade in your snow boots for slippers," and created networking events for filmmakers to mingle with audiences in "avatar" based chat rooms and virtual-reality cinemas.

"We had a choice to make – we could cancel or move the festival," said director Tabitha Jackson, opening the festival Thursday.

"Or we could take a risk and imagine a way to recreate the energy of the full festival experience digitally," she added.

"CODA" was based on French 2014 comedy "La Famille Belier," transplanted to the US fishing town of Gloucester by director and Massachusetts native Sian Heder ("Orange is the New Black.")

Both Heder and Jones learned sign language for the film, which features several prominent deaf actors in lead roles including Oscar-winner Marlee Matlin ("Children of a Lesser God.")

"This film has changed my life forever," said Jones, who told the virtual audience she was continuing to learn the "beautiful" language.

The movie employed real CODAs on set as translators where needed, and Heder said she hopes the film will inspire Hollywood to make more disability-focused films.

"We are hungry to hear new stories that we haven't heard... this is a world of new stories, in the disability world," she said.

Thursday also saw the premiere of "Summer of Soul (...Or, When The Revolution Could Not Be Televised)," musician Questlove's first movie about the huge "Black Woodstock" festival that took place in 1969 Harlem.

The documentary brings to light never-before-seen footage of the star-studded concert which was attended by 300,000 people and featured Stevie Wonder, Nina Simone and Mahalia Jackson, but has largely been lost to history until now.

Questlove, whose real name is Ahmir Thompson, deftly mixes euphoric concert scenes with historical background on "a pivotal year for Black and brown people all over the country" and a range of high-profile interviews.

Music "was the therapy for the stress and pressure of being black in America," recalls Al Sharpton, who reminisces in the film alongside Jesse Jackson and Mavis Staples. "We didn't know anything about therapists, we knew Mahalia Jackson."

Some 72 feature films will screen at the festival co-founded by Robert Redford, which runs through to Wednesday.

(Cover: Anne Hathaway attends "The Last Thing He Wanted" premiere during the Sundance Film Festival at Eccles Center Theatre in Park City, Utah, January 27, 2020. /CFP)